This proposal is for continuation of support for a 10 bed General Clinical Research Center and its associated laboratory in a large medical center for children closely affiliated with the Harvard Medical School, comprising 340 beds, with over 12,000 admissions and 170,000 out-patient visits per year. The research proposed, utilizing the facilities of the Clinical Research Center, will be carried out by members of the full-time staff from the Departments of Medicine, Cardiology, Neurology and Neurosurgery Ophthalmology, Psychiatry, Surgery, and Cardiovascular Surgery. Clinical investigations have as their goals the sharpening of methods of assessment, the deepening of understanding of fundamental processes at a molecular and cellular level, and improvement of the treatment of the following groups of disorders in children: immunodeficiency state disturbances of complement metabolism, and collagen diseases; hemoglobinopathies and red cell disorders, leukocyte dysfunction, bone marrow failure; inflammatory bowel disease, liver disease, and cystic fibrosis; disorders of amino acid metabolism; disorders of neuroendocrine function, testicular development and metabolism of steroid hormones, hypoglycemic states, complications of diabetes mellitus and progeria; the nephrotic syndrome, cystinosis, and disorders of Vitamin D metabolism; Reye's syndrome; hypoxic polycythemia, complete heart block, regurgitant valvular disease, chronic tachycardia and pulmonary hypertension; hydrocephalus and epilepsy; disorders of motor development in congenital brain anomalies, of psychological development with social deprivation, and of cognitive and sensory-motor performance in abnormalities of sex hormones or sex chromosomes; parenteral alimentation, and the control of immune responsiveness in allograft recipients; the use of extracorporeal oxygenation in pulmonary insufficiency.